Hydrocarbon conversion process



Oct. 1, 1946. v D, READ, JR 2,408,580

HYDROCARBON CONVERSION PROCESS v Original Filed April 29, 1940 72a zvzace YZ/zz for* @s @d/Jj? y @#0 ffrey Patented Oct. 1, 1946 HYDROOARBON CONVERSION PROCESS VDavis Read, Jr., Riverside, Ill., assignor to Universal Oil Products Company, Chicago, Ill., a.

corporation of Delaware Original application April 29,1940g-Serial' No. 332,136. Divided and this application Septem ber 27, 1943, Serial No. 503,903 Y 1 This application is. a division of Serial No. 332,136 filed April 29, 1940, which hasv matured into Patent No. 2,336,126, dated December 7, 1943.

This invention relates to a process for convert'- ing relatively wide boiling range hydrocarbon oils into high yields of high antiknockk gasoline and more specifically it is concerned with an improvement in the art of' cracking hydrocarbon Oil wherein a relatively heavy hydrocarbon Oil is non-catalytically cracked and relatively light hydrocarbon oil catalytically cracked in the presence of a catalyst suspended therein. The improvement principally involves quenching the stream of hydrocarbon oils containing the sus'- pended catalyst as it leaves the reaction zone to arrest the cracking reaction, whereby to reduce to a minimum the formation ofV carbonaceous and residual material.

IA have found that in the catalytic cracking of hydrocarbon oil in the presence of a catalyst suspended therein, the reaction is usually accomplished at high temperatures and if the catalyst isv allowed to remain in contact with the oil after the desired reaction is accomplished, vunusually high amounts of' carbonaceous materials are formed which are deposited with the catalyst in the separating zone.

In view of the above, my invention provides for quenching the stream of hydrocarbon oil containing the suspended catalyst as it leaves the reaction zone to reduce the temperature thereofl to a temperature below that at which cracking is effected, after whichthe mixture` is supplied to a vaporizing and, separating chamber wherein vaporous conversion. products are substantially separated from the heavier hydrocarbons and catalyst.

' In one specific embodiment, the invention comprises' subjecting a relatively heavy hydrocarbon oil to Pyrolytic cracking in a heating coil and communicating reaction chamber, separating non-vaporous liquid residue from the pyrolytically formed vaporous conversion products, simultaneously therewith commingling a slurryv of cracking catalyst with a relatively light hydrocarbon oil and passing the mixture through a reac tion zone wherein it isheated to a catalyticA crack.- ing temperature, 'quenching the heated stream of hydrocarbon oil and catalyst leavingv the. regg..

tion zoney to. arrest the cracking reaction,y supplying the quenched stream of. oil and. catalyst to aV vaporizingV and` separating chamber wherein said catalyst is reduced to a substantially dry powder containing a highl proportion of carbonaceous materials by separating therefrom the 2. Vaporous products, commingling said vaporous products with said pyrolytic vaporous conversion products and fractionating the mixture together with the charging oil to separate. fractionated vapors boiling in the range of gasoline from the higher boiling conversion products and charging oil, recovering said fractionated vapors, with-r drawing,V said higher boiling conversion products and charging oil as light and heavy refluX condensates, supplying said heavy reflux condensate to the pyrolytic conversion treatment as said relatively heavy oil andv supplying atleast a portion of said light reflux condensate to the catalytic conversion step as said relatively light hydrocarbon oil.

The accompanying diagrammatic drawing ilvlustrates in conventional side elevation one specie form of the apparatus which may be employed to accomplish the Objects of the invention.

kReferring how to the drawing, heavy reflux condensate formed in the manner to be described later is supplied to heating coil l. The heavy reflux condensate in passing through heating coil l is raised to the desired conversion. temperature which may range, for example, from 850 to 1000 F., or more, by means of heat supplied from furnace 2. The heavy reflux condensate leaving heating coilv l at an outlet pressure ranging, for example, from to 500 pounds or more vper square inchv is directed throughline 3 and valve 4 into reaction chamber 5. Reaction chamber 5 is preferably maintained atv substantially the' same pressure. or at a slightly lower pressure than `that employed onthe outlet of' heating coil l and is preferably insulated to reduce radiation losses therefrom, althoughno insulation is shown in the drawing. l A

The. heated reflux condensate in passing through reaction chamber 5 is subjected to `prolonged pyrolytic conversion at the elevated temperaturev and the resultingv conversion products are discharged therefrom through line 6 and valve 1 into Vaporizing and separating chamber 8. Vaporizing and separating chamber. 8 is preferably maintained at a reduced pressure relative to that employed in reaction chamber 5 ranging, for example, from substantially atmosphericv to 400 pounds or more per square inch in order to obtain a separation between the vaporous and liquid. conversionproducts and to effect substantial further vaporization of the liquid conversion products to forma non-vaporous liquid residue. Non-vaporous liquid residue separated in chamber 8 is removed therefrom by way of line 9- and valve I and may be recovered as a product of the process or subjected t0 any desired further treatment. Vaporous conversion products, together with vapors evolved within chamber 8, are directed through line Il and valve I2 into fractionator I3 for treatment in the manner to be described later.

Simultaneously with the pyrolytic conversion treatment of the heavy reflux condensate as above described, light reux condensate to which powdered catalyst is added in the manner to be described later, is supplied to heating coil I4. The slurry of catalyst and oil in passing through heating coil I4 is raised to the desired conversion temperature ranging, for example, from 500 to 1200 F., heat being supplied by means of furnace I 5.v

Preferably also, heat is supplied to the slurry of catalyst and oil in heating coil I4 at a rapid rate so as to minimize the amount of pyrolytic cracking effected and increase the amountl of catalytic cracking. When desired, a reaction zone other than a heating coil may be employed, however, in view of the fact that control of the heating is more readily obtained in a heating coil than in other types of reaction vessels the method illustrated is the preferred method.

The heated mixture of oil and catalyst leaving heating coil I4 at a pressure ranging, for example, from substantially atmospheric to 1000 pounds or more per square inch is directed through line I6 and valve Il and, in accordance with the objects of the invention, is commingled with a cooler stream of hydrocarbon oil introduced in the manner to be described later in order to quench the stream of hot oil to a temperature ranging, for example, from 400 to 800 F., and the resulting mixture ofconversion products, cooling oil, and catalyst is supplied to vaporizing and separating chamber I8. Chamber I8 is preferably operated at a reduced pressure relative to that employed on the outlet of heating coil I4 ranging, for'example, from substantially atmospheric to 400 pounds or more per square inch whereby to separate vaporous conversion products and catalyst.

Chamber I8 is operated as a catalyst separating chamber wherein the catalyst is reduced to a substantially dry powder containing a high proportion of carbonaceous materials formed by reducing the liquid residue to a substantially dry coke. It would be desirable to employ more than one chamber in order that one or more of the chambers may be cleaned while another or others are employed inthe conversion treatment. In this type of operation, the catalyst is removed as a substantially dry powder containing a high proportion of carbonaceous material and may be supplied to a catalyst regenerating system not shown in the drawing to prepare the catalyst for reuse.

The vaporous conversion products separated in chamber I8 are removed therefrom by way of line 33 and directed through valve 34 into .line I I, commingling therein with the vapors removed from chamber 8, which mixture is supplied to fractionator I3. Fractionator I3 and the condensing and receiving equipment in communication therewith are preferably operated at a superatmospheric pressure of the same order as that employed in chambers, 8 Yand I8. Simultaneously with the introduction of the vaporous products to fractionator I3, charging oil which may comprise, for example, a relatively wide boiling range hydrocarbon oil such as crude oilv or reduced crude oil or any desired fraction thereof,

4of the charging oil, the latter being withdrawn as light and heavy reflux condensates. Fractionated vapors separated in fractionator I3 are directed through line 48 and valve 4I to cooling and condensation in condenser 42. Distillate, together with undissolved and uncondensed gases from condenser 42, Lis directed through line 43 Vand valve 44.into receiver 45 wherein the distillate and gases are collected and separated. Normally gaseous products collected and separated in receiver 45 are removed therefrom by way of line 45 and valve 4l and recovered as a product of the process or subjected to any desired further treatment. A portion of the distillatecollected and separated in receiver 45 maybe returned to the upper portion of fractionator I3 to serve as a reiluxing and cooling mediumwhile the residual portion thereof maybe removed from receiver 45 by way of line 48 and valve 49 and recovered as a product of the process.

Heavy reflux condensate condensed and separated within fractionator I3 is removed therefrom by way of line 50 and is directed through valve 5I to pump 52, which discharges through line 53 and valve 54 into heating coil I, the heavy reflux condensate being subjected to treatment as previously described.

Light reflux condensate separated in fractionator I3 is directed through line 55 and valve 5S to pump 57. Pump 51 discharges through line 58 and a portion is directed through line 59 and valve .62 into line I5 to serve as a quenching oil as previously described. Still anothcr'portion thereof may be removed from the system by wayv of line 63 and valve 54 for use in preparing the catalyst slurry in the manner to be described later. The residual portion of the light reflux condensate in line 58 is directedthrough valve 65 and is commingled with a slurry of cracking catalyst preparedin the same manner to be described later and the mixture supplied to heating coil I4 for treatment as previously described.4

The catalyst slurry comprising, for example,A

a mixture of powdered cracking catalyst and light reflux condensate or any relatively light hydrocarbon oil of characteristics similar to those of the light reflux condensate is supplied tol the system by way of line 66 and is directed through valve 61 to pump 68 which discharges through line 69 and Valve 'I0 into line 58, commingling therein with the light reflux condensate as previously described.

Catalysts which have been found .to be effective in the catalytic cracking of hydrocarbon oils may comprise, for example, powder or granules of silica or other siliceous andrefractory materials composited with compounds selected from the group consisting of alumina, zirconia, vanadiaand thoria. In addition, the hydrosilicates of alumina, acid treated clays, or the like, have also been found to be effective in the cracking treatment of hydrocarbon vapors.

Although the catalysts above recited are generally considered to be the preferred catalysts, their use is not to be construed as a limiting feature, for various other catalysts wellknown to those in the art may be employed within the broad scope of the invention.

I claim as my invention: t

1. A process for the production oi motor fuel which comprises subjecting a relatively heavy hydrocarbon oil to pyrolytic cracking in a heating coil and communicating reaction chamber, separatingr non-vaporous liquid residue from the pyrolytically formed vaporous conversion products, simultaneously therewith kcorrm'iingling a slurry of cracking catalyst with a` relatively light hydrocarbon oil and passing the mixture through a reaction zone wherein it is heated to a catalytic cracking temperature, commingling a relatively cool oil with the heated stream of hydrocarbon oil and catalyst leaving the reaction Zone to arrest the cracking reaction, supplying the quenched stream of oil and catalyst to a vaporizing andseparating chamber wherein said catalyst is reduced to a substantially dry powder containing a high proportion of carbonaceous materials by substantially completely vaporizing the hydrccare bon introduced to said chamber and separating therefrom vaporous products substantially free of entrained catalyst, commingling the last-named vaporous products with said pyrolytic vaporous conversion products and fractionating the mixture together with the charging oil to separate fractionated vapors boiling in the range of gasoline from the higher boiling conversion products and charging oil, recovering said fractionated vapors, withdrawing said higher boiling conversion products and charging oil as light and yheavy reux condensates, supplying said heavy reflux condensate to the pyrolytic conversion -treatment as said relatively heavy oil and supplying a portion of said light reflux condensate to the catalytic conversion step as said relatively light hydrocarbon oil, and utilizing another portion of said light reflux condensate as said relatively cool oil.

2. A process for the production of motor fuel, which comprises subjecting a relatively heavy oil to pyrolytic cracking, separating the resulting conversion products into pyrolytic vaporous conversion products and non-vaporous liquid residue, simultaneously therewith commingling a relatively light hydrocarbon oil with powdered cracking catalyst to form a slurry, supplying the resulting slurry to a reaction zone wherein it is heated to a conversion temperature, quenching the stream of hot oil and catalyst leaving said reaction zone to arrest the cracking reaction by commingling therewith a colder stream of hydrocarbon oil, supplying the resulting mixture of cooling oil, catalyst, and catalytic conversion products to a vaporizing and separating chamber wherein said catalyst is reduced to a substantially dry powder containing a, high proportion of carbonaceous materials by substantially completely distilling therefrom vaporous products substantially free of entrained catalyst, commingling said vaporous products with said pyrolytic vaporous conversion products and fractionating the mixture together with the charging oil to separate fractionated vapors boiling in the range of gasoline from the higher boiling conversion products and charging oil, recovering said fractionated vapors, withdrawing said higher boiling conversion products and charging oil as light vand heavy reflux condensates, supplying said heavy reflux condensate to the pyrolytic conversion treatment as said relatively heavy oil, supplying a portion of said light reilux condensate to the catalytic conversion step as'said relatively light hydrocarbon oil, and supplying another portion of the light reiiux condensate to the aforesaid quenching step as said colder stream of oil.

3. A hydrocarbon oil conversion process which comprises fractionating the charging oil in contact with cracked vapors to form a relatively heavy fraction and a lighter fraction, thermally cracking theheavy fraction and separating re sultant cracked vapors from residual products, commingling a cracking catalyst with a portion of said lighter fraction and subjecting the resultant mixture to catalytic cracking conditions while passing through a conversion Zone, quenching the effluent of said conversion zone by commingling therewith another portion of said lighter fraction, separating the commingled materials into vapors and catalyst-containing residue, supplying thus separated vaporous products of the catalytic cracking and vaporous products of the thermal cracking to the aforesaid fractionating step for fractionation therein together with the charging oil, and iinally condensing the fractionated vapors.

DAVIS READ, JR. 

